Various means have been used for releasably attaching coated abrasive sheet material to a support surface on a tool to abrade a workpiece. Such means have included clamps which engage the ends of rectangular sheet material or the periphery or center of circular sheet material. Such clamps can be inconvenient to use, however, and may have separable parts or require the use of tools that can be misplaced.
Another approach has been to coat the back of the coated abrasive sheet material with pressure-sensitive adhesive and adhere it to a support surface of a tool which permits the sheet material to be peeled off after use. While such pressure-sensitive adhesive coated abrasive sheet material is relatively easy to attach and remove, the adhesive adds significantly to its cost. Also, adhesion to the support surface can be adversely affected if dust (which is normally present in the workplace) or water (which is used in some abrading processes) comes in contact with the layer of pressure-sensitive adhesive, so that new or partially used sheets must be carefully protected from such contact.
Some prior art attempts have been made to utilize magnetism for attaching coated abrasive sheet material to a support surface on an abrading tool; see e.g., U.S. Pat. Nos. 3,226,888; and 4,222,204. The structures for magnetically attaching described in these patents, however, apparently did not attach the coated abrasive sheet material to the support surface so that only the force of magnetic attraction and any force applied to the sheet material through the tool normal to the support surface would produce sufficient static friction between the coated abrasive sheet material and the support surface to retain the sheet material on the support surface while it was driven by the tool to abrade a workpiece. Instead these structures included mechanical interlocking rims or lugs to help retain the coated abrasive sheet material on the support surface, and portions of the structures incorporated with the coated abrasive sheet material added significantly to its cost.